For lift drives, motors having rotors equipped with permanent magnets are used. In this case, the rotors can be configured as inrunners having permanent magnets arranged at the outside or as outrunners having permanent magnets arranged at the inside. For equipping the rotor with permanent magnets, it is known to apply the magnets by hand to the surface of the rotor which represents a relatively large effort, however. Therefore, increasingly methods and devices enabling an automatic application of the magnets are used.
From the document EP 1 826 889 A1, a method and a holding device for applying magnets to a part are known. In this method, at least one magnet is applied to the surface of the part, wherein the magnet in the immediate vicinity of the part is retained in the holding device by a retaining force acting by means of a holding element. In this method, the magnet is first positioned relative to the part, and then the applied retaining force is reduced by deactivating the holding element so that the magnet is transferred to the surface of the part.
The document US 2005/246886 A1 describes a method for positioning and mounting magnets on a magnetic element of a motor. Herein, a magnet to be applied is retained in a holding device and positioned relative to the magnetic element. In this process, the magnet is retained by a force of attraction in a holding device. By lowering this force of attraction and/or by increasing a force pulling the magnet to the magnetic element, a transfer of the magnet to the magnetic element is effected.
From the document U.S. Pat. No. 4,748,738, a method for positioning a pair of magnets on a surface of an iron containing pole piece in a predetermined spatial relationship is known. In this method, the magnets are first held in a position by means of a retaining force. The magnets are subsequently caused to be transferred to the surface of the pole piece in their final position. This is achieved by pushing the magnets from slits by pushers.
The document DE 10 2004 039 807 A1 describes a method for mounting a permanent magnet with the front side of it at a support. In this method, the permanent magnet is held at the support by a first force. In this process, the permanent magnet is inserted into a holder so that the rear of the permanent magnet is supported by the holder and its front side protrudes from the holder. Subsequently, a second force directed to the rear side which is larger than or equal to the first force is applied to the permanent magnet. Subsequently, the holder is moved towards the support until the front side of the permanent magnet abuts the support. The second force is then diminished so that it is lower than the first force. Subsequently, the holder is retracted.
In the known methods, it is necessary to use additional elements such as pushers or to alter the acting forces by additional control measures.